Replacement for 6pin power ic "IDP=H02"

[sdancer75]

A Chinese power 6 pin IC smd with mark "IDP=H02". It removed from a adsl router power supply. Is there any chance to find the datasheet or even better a replacement one?

Regards

[fzabkar]

R7731A, Richtek, Burst Triple Mode PWM Flyback Controller, marking IDP=W, SOT-23-6:

https://www.richtek.com/assets/product_file/R7731A/R7731A-10.pdf

[sdancer75]

R7731A, Richtek, Burst Triple Mode PWM Flyback Controller, marking IDP=W, SOT-23-6:

https://www.richtek.com/assets/product_file/R7731A/R7731A-10.pdf

Excellent thanks 👍

Anyway, any idea how to test it?

Regards

[fzabkar]

R7731A, Richtek, Burst Triple Mode PWM Flyback Controller, marking IDP=W, SOT-23-6:

https://www.richtek.com/assets/product_file/R7731A/R7731A-10.pdf

Anyway, any idea how to test it?

One common fault in this topology is an open startup resistor between the Vcc pin and the rectified mains. Be aware that these faults leave 350VDC sitting on the bulk capacitor.

[sdancer75]

R7731A, Richtek, Burst Triple Mode PWM Flyback Controller, marking IDP=W, SOT-23-6:

https://www.richtek.com/assets/product_file/R7731A/R7731A-10.pdf

Anyway, any idea how to test it?

One common fault in this topology is an open startup resistor between the Vcc pin and the rectified mains. Be aware that these faults leave 350VDC sitting on the bulk capacitor.

Dead resistor between the Vcc and the rectified mains which are pin 5 Vdd (SOT 23-6?) and the point just after the rectifier bridge of the primary?

I suppose this is an smd resistor because in the primary top surface there is only one resistor which is fine. All parts was fine except the photo-resistor of the optocoupler which I replaced but it still dead.

Regards

[fzabkar]

Another common fault is that the capacitor on Vdd often dries out. I would also test for shorted outputs on the secondary side.

[sdancer75]

I tested everything from the top side ie all capacitors, mosfet, resistors etc. Everything was found ok except optocoupler. The smps stopped to work after a storm thunder ⚡⚡⚡.

All smd resistors from the back side seems to be also ok, so I suspect the pwm driver...

[fzabkar]

What voltage do you measure at Vdd?

[sdancer75]

Hi

I didn't test the power supply connected...it is dangerous, don't you think?

[fzabkar]

I didn't test the power supply connected...it is dangerous, don't you think?

Yes, it's dangerous. Ideally you would use an isolation transformer.